Research Plan: The general aim of this project is to determine, in obese postmenopausal women, if a program of combined regular aerobic exercise and dietary restriction, which reduces total and visceral fat and increases aerobic fitness levels, favorably modifies coronary heart disease (CHD) risk factors. Furthermore, I will determine if the improvements in these risk factors are related to reductions in abdominal visceral fat levels, total body fat levels, maximal oxygen consumption or treadmill time to exhaustion. To achieve this general aim, over a five-year period 80 otherwise healthy obese postmenopausal women will undergo extensive screening and baseline measurements followed by random assignment to either a program of combined regular aerobic exercise and dietary restriction or attention control (stretching and light calisthenics). Body composition, abdominal visceral fat levels, aerobic fitness and other CHD risk factors will be determined at the end of 17- weeks and at 34-weeks. The clinical significance is that if these risk factors as a whole can be favorably modified, the risk for subsequent morbidity and mortality would also be reduced in this high risk population. In addition, the results would provide an experimental basis for the therapeutic use of this combined intervention for the treatment of obesity in postmenopausal women.